This Phase II SBIR proposal aims at the continued development and commercialization of a new class of high-performance X-ray imaging screens based on the recently developed core/shell nanorod (NR) and nano-tetrapods (NTs) structures. These multi-dimensional nanocrystalline (NC) structures can be easily embedded with high densities in transparent polymer matrices. They will have wide ranging applications in digital radiography, mammography, tomography, protein crystallography, as well as a various large-area radiation imaging and detection applications, never before possible using conventional scintillators. The goals of Phase I were successfully achieved and we have demonstrated the potential for high spatial resolution, very fast time response, no afterglow, no self-absorption, and good X-ray conversion efficiency. The nano- composite scintillators were prepared and tested independently by both PhosphorTech and Radiation Monitoring Devices (RMD) and have outperformed conventional organic and inorganic bulk scintillators on several fronts. During Phase II, our plan is to continue refining these NC structures and related screening/growth techniques and demonstrate their ability to outperform even single crystal X-ray scintillators in terms of resolution, detection area, gain, and production cost. This will be achieved by creating NCs with optimal lengths and narrow size distribution and then incorporating them into polymer composites containing orderly arrangement of such structures at high packing densities. The orderly NC arrangement, which will be achieved by well-established low-cost solution-based self-assembly techniques, will dramatically enhance X-ray absorption and facilitate light channeling through the polymer matrix to the electronic sensors. Using such methods, it is possible to attain very long (tens of microns) vertically aligned NCs in a polymer matrix with inter- NC spacings (that can act as light channels) of only few nanometers, as opposed to the micron spacing limitations provided by conventional CsI and other single crystal (or bulk powder) scintillating structures. The low-cost solution processing methods employed in these systems will also enable both large-area and high resolution scintillators with significant cost reduction compared to conventional bulk and single crystal materials. In summary, these novel NC-based films will have significant applications in various types of radiation detection devices, and other biomedical imaging applications, enhancing their value to the NIH and to the molecular biology and medical communities as a whole.